My son is had turned 18 last August and graduated from High School. He made it clear that he is not interested in going to college at this time. He is very motivated to working which he is.

Does that disqualifies the mother to continue receiving child support.If so, what is the course of action to stop the payment.

Don't get me wrong, I have a good relationship with son and want what's best for him. But I am not sure how he get a High Diploma given his attendance in school.

You need to re-read your child support clause in your divorce paperwork. If it says that the support stops when he's 18, then it stops. If it says it stops after college or when he's 21 then it stops. If you are wise and wish the support to stop you must petition the Court to terminate your child support. In some states the child support does not legally end until a Judge signs an Order terminating it. If you pay through the Child Support Agency I would suggest contacting them directly and see what peramaters the particular child support order you have in place applies toward ending the support.

As noted, this should be spelled out in your support order. Also some states support continue to 21. ANY question about law NEEDS to include your general area as laws vary.